Sen. Bernard Sanders, I-Vt., will host a screening of a new documentary about financial inequality Sunday morning in South Burlington.

Robert Reich is the star of a new movie. And Bernie Sanders probably could have written the script.

This weekend, the two men will host a screening of Reich’s new documentary, “Inequality for All.” Reich and Sanders have been preaching the same progressive gospel for years. And Reich says the message finally seems to be resonating.

“In the 30 or more years that I’ve been working on this problem, I have not seen more action and discussion,” Reich said by phone from California on Friday. “Even the president is talking about this as the defining challenge of our time.”

Reich is an economist, professor and political commentator who spent fours as secretary of labor under President Bill Clinton. He’ll appear by phone at the Palace 9 Cinemas in South Burlington on Sunday, where Sanders is inviting people to watch the move for free, and participate in a discussion about it afterward.

Reich says the 400 richest people in America now have as much wealth as the bottom 150 million put together, and he says the income gap hasn’t been this severe since the 1920s. He says the trend threatens the fundamentals of the U.S. economy.

“The vast middle class and working class and poor don’t have enough purchasing power to keep the economy going,” Reich says. “And that’s one reason why this recovery has been so lackluster and so anemic relative to previous recoveries.”

Reich and Sanders are advocating for a list of policy reforms they say will rectify the imbalance. Reich says raising the minimum wage and expanding the earned income tax credit will deliver immediate financial relief to citizens on the bottom rungs of the economic ladder. He says increasing taxes on the wealthy will underwrite the public investments needed to lift the underclass.

But Reich says getting money out of politics and overturning the Supreme Court’s Citizens United decision are also necessary steps in the reformation of the American economy.

“When so much income and wealth is concentrated in so few hands, our democracy is undermined, because almost inevitably, with money goes political power,” he says.

The ideological battle over economic theory isn’t confined to national politics. In Vermont, some Democratic and Progressive lawmakers are pushing for higher taxes on the wealthy. But they’ve been rebuffed so far by Democratic Gov. Peter Shumlin, who says rich people will flee the state if Vermont goes after their wealth.

Reich says states like Vermont have to balance concerns over competitiveness against the benefits of propelling change.

“No state wants to make itself uncompetitive by raising its costs too high relative to other states,” Reich says. “And yet, we can to some extent create a race to the top rather than a race to the bottom.”